Biochemical and ligand binding properties of recombinant Xenopus laevis cortical granule lectin-1

Peerapon Deetanya; Thassanai Sitthiyotha; Nusara Chomanee; Surasak Chunsrivirot; Kittikhun Wangkanont

doi:10.1016/j.heliyon.2022.e10396

Biochemical and ligand binding properties of recombinant Xenopus laevis cortical granule lectin-1

Heliyon. 2022 Aug 20;8(8):e10396. doi: 10.1016/j.heliyon.2022.e10396. eCollection 2022 Aug.

Authors

Peerapon Deetanya^{1

2}, Thassanai Sitthiyotha³, Nusara Chomanee⁴, Surasak Chunsrivirot³, Kittikhun Wangkanont^{1

2}

Affiliations

¹ Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
² Center of Excellence for Molecular Crop, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
³ Structural and Computational Biology Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
⁴ Electron Microscopy Unit, Department of Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.

Abstract

Intelectins are putative innate immune lectins that are found throughout chordates. The first intelectin reported was Xenopus laevis cortical granule lectin-1 (XCGL-1 or XL-35). XCGL-1 is critical in fertilization membrane development in Xenopus. Here, we explored the biochemical properties of XCGL-1. The cysteines responsible for forming intermolecular disulfide bonds were identified. XCGL-1 adopted a four-lobed structure as observed by electron microscopy. The full-length XCGL-1 and the carbohydrate recognition domain (CRD) bind galactose-containing carbohydrates at nanomolar to micromolar affinities. Molecular modeling suggested that galactoside ligands coordinated the binding site calcium ion and interacted with residues around the groove made available by the non-conserved substitution compared to human intelectin-1. Folding conditions for production of recombinant XCGL-1 CRD were also investigated. Our results not only provide new biochemical insights into the function of XCGL-1, but may also provide foundation for further applications of XCGL-1 as glycobiology tools.

Keywords: Intelectin; Omentin; XCGL-1; XL35; Xenopus laevis cortical granule lectin-1.